1. Field of the Invention
The present invention generally relates to a document management apparatus which manages a group of documents stored in a document storage device, and more particularly to a document management technique which extracts related documents, related to a currently processed document, from the group of stored documents in order to help the user process the current document.
2. Description of the Related Art
Currently, various document processing methods for extracting related documents from a group of stored documents are known. For example, a computer file system which performs a document management using a multilevel hierarchy of directories is known. Several retrieval tools that use the keyword search to find out a document containing specified words from a group of stored documents are known. A World-Wide Web (WWW) system is capable of linking documents, which are related to each other, into an information database that is stored in computers. A WWW browser is provided with a function to display a fixed number of viewed document records for a fixed period of time. In addition, another WWW browser is provided with a capability of determining ranking of stored documents by the frequency of reading of each document.
Generally, when the user performs document operations, such as document processing, storing, printing or viewing, there is a demand for extracting related documents, which are related to the currently processed document, from a group of stored documents. In addition, there is a demand for managing a collection of related documents that are related to a specific document.
In the case of the method using the hierarchy of directories on the computer file system, it is necessary to classify the documents into categories and determine the location in the directories where each document is stored. As the number of the stored documents increases, it is also necessary to change the document classification. The workload related to the document classification and the change thereof will grow accordingly.
In the case of the method using the keyword search, it is possible to find out related documents containing specified words from a group of stored documents. However, the inputting of a keyword list to the computer is required. Selection of a keyword list appropriate to find out the related document is a difficult task to be done.
The use of the WWW system facilitates the retrieval of related documents. However, it is necessary to perform preparatory tasks to determine the relation of the respective documents and generate the links between the related documents before the information database is stored in the computers.
Japanese Laid-Open Patent Application No.2000-20202 discloses a document management method. In the document management method disclosed by the above publication, a number of viewed data records are analyzed in accordance with selection criteria of importance parameters specified by the user. According to the results of the analysis, a list of viewed data records having higher values of the importance parameters is displayed by using user-defined symbols.
Although the above-mentioned method allows the user to look into the viewed data records having higher values of the importance parameters, it does not facilitate retrieving the data of the related documents, which are related to the currently processed document, from the group of stored documents. In the above-mentioned method, the user is required to define the relationship between the symbols and the selection criteria before the displaying of the list of viewed data records is performed.
Japanese Laid-Open Patent Application No.7-282059 discloses a document management method. In the document management method disclosed by the above publication, a degree of relation is calculated for each of related documents, which are currently processed by the user. The degrees of relation of the related documents are displayed to provide the user with a view of an entire structure of relation of all the related documents.
However, in the above-mentioned method, the degrees of relation of the related documents are not stored in the system after the end of the document processing. It is impossible for the user to access the relation data of the related documents previously calculated, when the user returns to process the same document later.